On the face of it, the teacher's strike in Chicago is about money, job security and how teachers are evaluated. But it's also about the political pressure on teachers' unions to make concessions that not long ago would've been unheard of. Teachers' collective bargaining rights these days have taken a backseat to bare-bones budgets and to claims that unions are an obstacle to efforts aimed at improving the quality of schools. As NPR's Claudio Sanchez reports, all these elements have come together in Chicago.

CLAUDIO SANCHEZ, BYLINE: If you ask Randi Weingarten, president of the American Federation of Teachers, why the Chicago teachers strike is important, she chooses her words carefully.

RANDI WEINGARTEN: This is a local situation that has national ramifications.

SANCHEZ: Weingarten is walking a fine line. On one hand, she supports the strike because she says teachers in Chicago are hurting.

WEINGARTEN: They don't have the right class sizes for kids. They don't have, you know, social workers for kids. They don't have guidance counselors for kids. They don't have libraries for kids. They don't have nurses for kids.

SANCHEZ: On the other hand, Weingarten has worked very hard to promote her union as a champion of reforms that call on teachers to agree to big changes.

WEINGARTEN: We all have to change to help improve public education.

SANCHEZ: The problem says Anthony Cody is that union leaders like Weingarten have made too many concessions in the name of reform. Cody is a former teacher and activist opposed to the Bush-era No Child Left Behind law and President Obama's Race to the Top policies.

ANTHONY CODY: So it's up to the teachers of Chicago, it's up to the teachers of Los Angeles, New York, Oakland everywhere else to lead from the bottom and that's what teachers in Chicago were doing. And I think there's a lot of us that are really ready to follow them.

SANCHEZ: In other words, says Cody, don't look to the unions' national leaders to protect teachers from pay for performance or schemes that tie teacher evaluation to students' test scores. This internal conflict over the role of unions in school reform comes at a bad time for unions because big city mayors, regardless of party, are more willing to take them on.

JOE WILLIAMS: You're starting to see management start to act like you would expect management to act.

SANCHEZ: Joe Williams heads Democrats for Education Reform. He takes the position that the Democratic Party should be pushing tougher reforms, which is exactly what Chicago Mayor Rahm Emanuel is doing.

WILLIAMS: Looking after the taxpayer, looking after the students, looking after the bottom line. And it's created some fault lines which are pretty tricky to get over right now.

SANCHEZ: Still, Williams says the strike in Chicago could embolden anti-reform factions within teachers' unions. Nonsense, says Dennis Van Roekel, president of the National Education Association, the nation's largest teachers' union.

DENNIS VAN ROEKEL: And to insinuate that somehow this is a movement for unions to rebel against education reform, that's crazy because unions across this country are leading education reform.

SANCHEZ: The NEA supports the Chicago teachers' strike, which Van Roekel says will be settled. And it won't be at the expense of meaningful school reform. The question is: Will there be anything left of the old alliances between teachers' unions and their democratic partners, especially with a presidential election right around the corner. Again, Joe Williams of Democrats for Education Reform.

WILLIAMS: I've got to think that President Obama's team is watching these developments very, very carefully. And I don't think that it's in anybody's interest for this to drag out for a long time.

SANCHEZ: The longer it takes the more time teachers will have to dwell on a key question: Should teachers continue to support a party that they think no longer backs them?